The use of low-value imaging: the role of referral practice and access to imaging services in a representative area of Norway.

Background: Even though imaging is essential to modern medicine, some examinations are of low value as they do not lead to any change in the management of the patient. The Choosing Wisely (CW) campaign aims to reduce the use of such services. In the Norwegian version of CW, specific magnetic resonance imaging (MRI) of the head, lower back, and knee are amongst others identified as potential low-value examinations. However, referral practice and access to imaging may drive low-value utilisation. By using registry data from 2019 and descriptive analysis, this study aimed to examine the role of referral practice and access to imaging on the use of specific CW-examinations in one representative area in Norway. Results: A total of 237,554 examinations were performed by four public and two private imaging facilities located within the area. Forty-two percent (19,210/45,289) of all MRI examinations were related to CW. Private imaging centres performed most of the CW-imaging. A total of 3700 referrers were identified, and 2.3% were identified as "high-referrers," accounting for 33% of all CW-examinations. Referrers' experience did not influence imaging utilisation. A subset of referrers ("super-referrers," 0.5%) accounted for 10% of CW-examinations. Distance to service had no impact on the use of CW-examinations. Conclusions: This study provides valuable insight into the use of imaging and referral practice in one representative area in Norway. A great variation in referral practice was observed. Therefore, targeting referrers with high referral rates may be a promising strategy for reducing the use of low-value imaging. Key points: MRI is frequently used, and a substantial proportion of MRIs are potential of low value. A small number of referrers account for a large proportion of potential low-value imaging. The use of imaging is not associated with travel distance to imaging facilities or referrers' experience. Targeting "high-referrers" may be a promising strategy for reducing low-value imaging. [ABSTRACT FROM AUTHOR]